1. Field of the Invention
The invention relates to an apparatus for agricultural sprayers for spreading pesticides on fields and plants, e.g. on standing crops, in orchards, or in vineyards, comprising at least one pesticide container, a dosage pump for the container or the containers, respectively, or for each container, and a control unit for adjusting the pump flow or the pump flows, respectively, in dependence on definite parameters, the driving speed being one.
2. Description of the Prior Art
Dose control apparatus of this type is used on agricultural sprayers which in the tank provided thereon carry not a mixture of plasticide and water in a predetermined mixture ratio but pure water only, the pesticide being admixed to the water flow to one or more nozzle ramps. The advantage of this system is primarily that the dosage, i.e. the mixture ratio between water and pesticide can be changed during driving of the sprayer to be adjusted to local variations in the need of pesticide on the field or plant region which is being treated, and that the tank of the sprayer contains pure water and will never be contaminated by pesticide so that it is not necessary to clean the tank when changing from one pesticide to another or at changeover Lo spreading of other substances than pesticides, such as fertilizers.
In known embodiments these dose control apparatuses do not operate in a satisfactory way, however, because the precision of the dose control is deficient so that the mixture ration cannot be adjusted and maintained with the accuracy required and the mixture of water and pesticide will not be homogeneous so that the pesticide concentration will vary in different parts of the nozzle ramp or ramps.